Pipes typically known as ‘Quick Connect’ pipes and joints systems made using these pipes have been used in sprinkler irrigation since last so many years. These joints are easily assembled and disassembled in field conditions and used in systems for conveyance of pressured fluids. Pipes used in such systems are typically the extruded type. The male and female ends are manufactured separately by injection moulding. The moulded ends are welded to a pipe's plain ends to make a pipe length suitable for joining with other pipes. Each pipe thus has a male and a female end.
The male and female ends can be welded to the pipe in a number of ways such as butt fusion welding, socket fusion welding etc. The female sockets are further machined to form grooves for placing rubber rings that help form a seal. Waste material produced during the grooving process is normally recycled. The pipes fitted with male and female ends thus produced are easily connected with and disconnected from each other. In the case of systems carrying fluids under pressure, a clamp is used to hold securely the joints thus formed to withstand pressure, and sealing rings are used to make the joints leak-proof.
Piping systems with easily assembled and disassembled coupling arrangements used for conveyance of pressured fluids are available. An ideal pipe system that is deployed in transportable sprinkler irrigation systems which are operated under pressured fluids should be designed so that the following requirements are met:                It withstands the applied pressure.        It is easy to install and dismantle in field.        The joints are leak-proof        The pipe ends, which are generally prone to damage, are unbreakable.        The pressure drop should be minimum.        The system must be cost effective.        
Many of the existing piping systems used for sprinkler irrigation fulfill the first three requirements from the above list of requirements, however, most of these systems suffer from drawbacks such as:                The welds of male and female ends can fail if proper welding procedures are not followed.        The welded joints, due to their roughness and irregular surface, cause restriction to flow of water, which results in pressure drop across the joint.        The joints are created using injection moulding technique thus requiring heavy investment in injection moulding machine and equipment, in a business that otherwise would be operating on a extrusion technique.        A separate huge inventory of moulded articles needs to be maintained to fulfill requirements on time, leading to huge space requirement.        Substantial amount of welding equipment is required to manufacture welded joints in large quantities.        The welded joints also require to be machined to the required groove in moulded female end which also generates waste.        Another drawback is that the existing systems typically require skilled manpower to produce good quality welded joints.        Weld quality can vary dependent upon the operator skill        In order to overcome the restriction-to-flow drawback, there have been attempts to make the inner edge of the pipe at the plane of the joint as smooth as possible by a debeading operation. This helps in reducing the flow restriction, which ultimately reduces pressure drop over the length of the joint. However, this method is not effective in sprinkler piping system as the pipes used are generally thin walled and debeading operation poses a serious risk to the integrity of the weld joint, possibly resulting in weld failure. The debeading operation is also time consuming and thus increases the cost of the irrigation system.        There have been attempts to eliminate the post-forming operation of machining grooving in a moulded female end. In one such attempt, a collapsible mould was used to form groove directly, however, shrinkage could not be controlled effectively, as a result of which the grooves formed were not of good quality. Uneven shrinkage properties of polyolefin during moulding lead to change in article wall thickness. The uneven shrinkage ultimately results in problems relating to sealing of joints and assembling the pipe system.        In the U.S. Pat. No. 5,554,332, Schnallinger discloses a process of manufacturing shaped elements from synthetic thermoplastics, in which plastic material (synthetic thermoplastics) is heated to a temperature above its softening point and shaped to form the shaped element. The shaped element is subsequently cooled to a temperature below its softening temperature.        However, Schnallinger did not teach how to create a thermoplastic pipe that has an integrally formed male spigot and a female socket at once. Nor did he teach how to make a leakproof joint from a thermoplastic pipes with such male and female ends.        There is therefore a need to provide a system of joints which will fulfill all the requirements as specified above for long life working of piping system used in sprinkler irrigation at lowest cost, and which will not suffer from any of the drawbacks mentioned above.Objectives and Advantages:        
Accordingly, the objectives & advantages of the present invention are as described below.
An objective of the invention is to provide a system of joints suitable for use in irrigations system and made from pipes that are provided with integral male & female ends so as to:                Eliminate the need for injection moulding of male & female ends.        Eliminate the need for welding activities.        Eliminate the risk of welded joint failure.        Minimize the pressure drop across the pipe joints.        Eliminate the coupler grooving activities.        Eliminate the material wastages during female end groove machining.        Ensure that the system will withstand the pressure applied in the system and is leak proof        Ensure that the system is easy to install & dismantle in field        Ensure that the system does not suffer from shrinkage effects        Ensure that the system is cost effective.        
Another object of the present application is to provide a process by which the pipes with integrally formed male and female ends proposed in this invention are manufactured.